You don't have to
You don't have to be an expert in history to know all of what happened. The film is very interesting. The theme is that the "fake world" is not only a myth but also a reality. And the characters seem to have a real sense of their own reality. And the film is very touching.
You don't have to be such a stupid person to hate this rubbish. It was a total waste of time and money for me.